This invention relates to a system for feeding carbonaceous materials such as agglomerative coal particles into a pyrolysis reactor.
In a typical process for coal conversion by pyrolysis, coal particles are fed through a feed tube into a pyrolysis reactor. The coal particles typically are suspended in a non-deleteriously reactive fluid carrier, such as nitrogen gas, and are mixed in the reactor with hot char particles at a temperature of about 600.degree. F. or more. The hot char particles are normally suspended in a non-deleteriously reactive carrier fluid, such as nitrogen gas, at about the same temperature. When the coal particles are agglomerative, the fluid carrier must be kept relatively cool prior to injection of the coal particles into the hot stream of char particles to prevent agglomerative plugging of the feed tube.
In the past, agglomerative coal particles have been fed into the hot stream of char particles by connecting the feed tube to the side wall of a curved conduit carrying the stream of char particles to the reactor. The feed tube has been connected along the outside of a bend of the conduit. Excess heating of the coal particles in the feed tube has been avoided because the feed tube terminates at the side wall of the conduit. The feed tube does not extend into the reactor. However, the char particles concentrate around the outside of the bend in the conduit due to centrifugal force. As a consequence, some of the particulate agglomerative material reaches the wall of the reactor before it passes through the agglomerative state. This causes an agglomerative mass to form on the walls of the curved conduit leading to the reactor near or at the attachment of the feed tube to the curved conduit. Thus, the coal particles eventually plug the mouth of the feed tube.